A galaxy cluster some 10.2 billion light years away has been named as the furthest from Earth ever found.
The group of galaxies, known as JKCS041, beats the previous record holder by around a billion light years. It appears as it was when Earth was only a quarter of its present age.
The bunch, containing hundreds of galaxies, was analysed by combining data from Nasa's Chandra X-Ray Observatory with data from optical and infrared telescopes.
Galaxy clusters are the largest gravitationally-bound objects in the Universe. Scientists hope that the findings will help them learn more about how the Universe evolved.
JKCS041 was first detected in 2006 with infrared observations. But scientists were not sure if it was a true galaxy cluster, rather than one in the act of forming.
Nor could a normal telescope tell them how far away it was.
Dr Ben Maughan, from the University of Bristol, carried out a long-term analysis of the Chandra X-ray data which has finally proved JKCS041 to be a fully-formed cluster.
Dr Maughan said: "This discovery is exciting because it is like finding a Tyrannosaurus Rex fossil that is much older than any other known.
"One fossil might just fit in with our understanding of dinosaurs, but if you found many more you would have to start rethinking how dinosaurs evolved. The same is true for galaxy clusters and our understanding of cosmology."
JKCS041 is at the farthest point at which scientists think galaxy clusters can exist in the early Universe.
Studying its characteristics - such as composition, mass and temperature - should therefore reveal more about how the Universe took shape.
Stefano Andreon of the National Institute for Astrophysics (INAF) in Milan, Italy, said: "This object is close to the distance limit expected for a galaxy cluster. We don't think gravity can work fast enough to make galaxy clusters much earlier."
Searches are under way to find other galaxy clusters at extreme distances to enable further comparison.
The previous record holder for a galaxy cluster was the 9.2 billion light years away XMMXCS J2215.9-1738, discovered by ESA's XMM-Newton in 2006.
This broke the previous distance record by 0.1 billion light years.
Mr Andreon added: "What's exciting about this discovery is the astrophysics that can be done with detailed follow-up studies."